In system designs used for Digital Subscriber Line (DSL) broadband networks, there is push to move much of the deployment electronics from the network Central Office to locations near the building being served. Fiber optic cables are brought from the Central Office up to a pit or vault where the fiber optic cable meets the copper wire interface to the twisted pair copper wire network for the building. Coupling of the fiber optic cable to the copper wire interface is achieved through a deployment (Dp) unit, often referred to as a Fiber to the Home Deployment (FTTDp) unit. As opposed to bringing power to the deployment unit from the Central Office, reverse powered FTTDp units are now often utilized. This avoids may of the problems associated with powering deployment units from the Central Office, such as the expense of installing the necessary equipment and cables, as well as voltage drop and other power management issues. Instead, power to the deployment unit is supplied directly from the building being serviced by the deployment unit. However, the only electrical conductors typically available in the pit with the deployment unit are the twisted pair wires. This means that reverse powered FTTDp units need to be supplied DC power over the same conductors that carry high bandwidth AC signal QAM modulated DSL signals. Power and DSL signals must co-exist on the same cable.
Typically this has been accomplished by installing two bias-T networks on the twisted pair lines: one within the building being served and one at the deployment unit. The first bias-T network within the building is coupled to a power supply unit that is powered from a building supplied electrical circuit. This first bias-T network may be referred to as a power injector because it adds DC power onto the twisted pair lines going to the deployment unit. At the deployment unit, the second bias-T network, often referred to as a power splitter, takes the DC power off the twisted pair lines to power the deployment unit. The power injector and power splitter need to be designed so that the DC power on the copper wires ideally does not load or otherwise affect the differential driven xDSL service. Legacy DSL system operated at a relatively low frequency range, starting at 32 KHz. However, modern DSL signals such as VDSL 30 may operate at frequencies up to 30 MHz, and upcoming protocols such as VDSL/G. Fast will operate at higher data bandwidths (for example, up to 106 MHz or up to 212 MHz or greater), where signal integrity is of paramount importance. Consequently, any imbalances or notches in the frequency band caused by parasitic loads from the power injector or power splitter will have increasingly detrimental effects on the overall bandwidth which the copper wire can support.
For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the specification, there is a need in the art for alternate systems and methods for Enhanced High Frequency Power Bias Tee Designs.